Monitoring Insect Transposable Elements in Large Double-Stranded DNA Viruses Reveals Host-to-Virus and Virus-to-Virus Transposition

Abstract

The mechanisms by which transposable elements (TEs) can be horizontally transferred between animals are unknown, but viruses are possible candidate vectors. Here, we surveyed the presence of host-derived TEs in viral genomes in 35 deep sequencing datasets produced from eleven host-virus systems, encompassing nine arthropod host species (five lepidopterans, two dipterans and two crustaceans) and six different double-stranded (ds) DNA viruses (four baculoviruses and two iridoviruses). We found evidence of viral-borne TEs in 14 datasets, with frequencies of viral genomes carrying a TE ranging from 0.01 to 26.33% for baculoviruses and from 0.45 to 7.36% for iridoviruses. The analysis of viral populations separated by a single replication cycle revealed that viral-borne TEs originating from an initial host species can be retrieved after viral replication in another host species, sometimes at higher frequencies. Furthermore, we detected a strong increase in the number of integrations in a viral population for a TE absent from the hosts’ genomes, indicating that this TE has undergone intense transposition within the viral population. Finally, we provide evidence that many TEs found integrated in viral genomes (15/41) have been horizontally transferred in insects. Altogether, our results indicate that multiple large dsDNA viruses have the capacity to shuttle TEs in insects and they underline the potential of viruses to act as vectors of horizontal transfer of TEs. Furthermore, the finding that TEs can transpose between viral genomes of a viral species sets viruses as possible new niches in which TEs can persist and evolve.

Horizontal transmission of functionally diverse transposons is a major source of new introns

“…Viruses are frequent vectors of horizontal transfer and may underlie transmission of TEs between diverse taxa (41)(42)(43)(44)(45)(46)(47). A bioinformatic search across our dataset revealed several cases of introners within viral genes integrated within host genomes (table S10; see Methods).…”

Unravelling The Complexities of Cervical Cancer: A Comprehensive Exploration

“…Oncogenic viruses, including HPV, play multiple roles in carcinogenesis. HPV, a sexually transmitted double-stranded DNA virus with high-risk strains classified within the Papovaviridae family, has over forty variations identified in the genital tract, categorized into high-risk and low-risk based on their carcinogenic potential 9 . Despite advancements in understanding HPV's natural history, oncogenic potential, and preventive strategies, HPV infection rates persist, particularly in developing nations with elevated CC incidences.…”

Closing the Knowledge Gap: Horizontal Transfer of <em>Mariner </em>Transposons between <em>Rhus</em> Gall Aphids and Other Insects

“…With the advancement and invention of new technologies, large scale analysis of different organisms genomes, several host and parasitic features can be considered to facilitate the occurrence of HTT, including the occurrence of some parasites with multiple host species, while a symbiotic association between different species could also leverage the phenomena of HTT among different species [22]. TE research community has evaluated many vectors with little or no success while some studies have hypothesized that parasites can mediate transfer of TEs from one species to another while some recent studies proposed that viruses can be the possible vectors that mediate HTT [23][24][25][26].…”